MQTT的使用

客户端重连机制

    public static void Reconnect_Using_Timer()
    {
        /*
         * This sample shows how to reconnect when the connection was dropped.
         * This approach uses a custom Task/Thread which will monitor the connection status.
         * This is the recommended way but requires more custom code!
         */

        var mqttFactory = new MqttFactory();

        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();

            _ = Task.Run(
                async () =>
                {
                    // User proper cancellation and no while(true).
                    while (true)
                    {
                        try
                        {
                            // This code will also do the very first connect! So no call to _ConnectAsync_ is required in the first place.
                            if (!await mqttClient.TryPingAsync())
                            {
                                await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);

                                // Subscribe to topics when session is clean etc.
                                Console.WriteLine("The MQTT client is connected.");
                            }
                        }
                        catch
                        {
                            // Handle the exception properly (logging etc.).
                        }
                        finally
                        {
                            // Check the connection state every 5 seconds and perform a reconnect if required.
                            await Task.Delay(TimeSpan.FromSeconds(5));
                        }
                    }
                });

            Console.WriteLine("Press <Enter> to exit");
            Console.ReadLine();
        }
    }

基本API的使用